y = 4x - 4
y = mx + c
First find the gradient.
6 - 2 = 4
Your gradient, m, is 4x.
Now find the constant, c.
y = mx + c
if y = 4 and x = 2
4 = 4 * 2 + c
4 = 8 + c
4 = 8 - 4
c = -4
y = 4x - 4
You can check it's right by substituting the other values.
y = 4x - 4
E.G
36 = 4 * 10 - 4
36 = 40 - 4
